View Full Version : ATF: Landmark - Gray tank question (a little long)

07-04-2012, 06:44 AM
I have somewhat of an embarrassing question. Embarrassing because we have been rving for many years and have of course opened and shut our gray water tank valves many times. We pulled into Ocean Lakes cg on Thursday night around 10:00 and began the set up process. Once I got the sewer hose connected I pulled the gray 1 and gray 2 tank valves and went on to finish my set up. There are 4 of us using the shower this week.On Saturday night our neighbor came over and told us that water was pouring out the under belly. Walked around behind the camper and found that I had opened the gray 1 and 2 tank valves in the udc but, I had forgotten to pull the handle on the valve I had installed at the end of the drain line.Opened the valve and let the water drain out of the tank.I checked to see if the basement had any water in it around the shower drain. I thankfully didn't find any. Water has continued to drip from the under belly since Saturday night, but I knew all the insulation in the underbelly near the gray tank was soaked and thought I would just wait till I got home to check everything out. After thinking about it for a couple days and since I have had the underbelly near the grey water tank down before and knew it wasn't that big of a deal to take down , I dropped it yesterday afternoon. Pulled out the soaked insulation and plan to let everything dry out before I close it back up. I didn't think I had a leak in the tank but I filled the grey tank up and looked for a leak but found none. Now finally here is my question to the factory. Is there an overflow of some type on these tanks? I can't find any trace of water between the shower and the tank. The only place I have found water where it shouldn't be is in the underbelly.Thanks

07-04-2012, 07:00 AM
Terry, I don't think that there is an overflow on the tanks. But it is possible that the water may have leaked out from the vent pipe connection. You have never had that much water in the tank so it has never showed up until this time. I hope you and Renee are enjoying your vacation!!!!

07-04-2012, 07:05 AM
If you drove in the rain or through water this may have been just rain water, known to happen.

07-04-2012, 07:13 AM
Grey 1 is near full (shower) grey 2 is partially full.
You pull both handles and not the main drain.
Tanks equalize. Your grey 2 is now "full".
My first place to look would be the grey 2 vent pipe connection.

Close the valves and run the sink.
Good chance a slow leak will still cause a big rush if water. As it slowly fills the underbelly until it can't hold anymore.

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07-04-2012, 08:21 AM
Thanks everyone for your replies. I hadn't driven in the rain so I know it wasn't that. The vent pipe connection sounds like where the problem is. Thanks again. I will check it out more when I get home.

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Terry H
07-04-2012, 09:44 PM
On my previous Big Horn I had a intermittent leak on Gray Tank #2. It took a long time to find. What I finally found was that the drain fitting that is threaded into the top of the tank had cracked. It only leaked when tank was over filled. Feel on the top of the tan in the center that is where the water will pool. I replaced the fitting and the leak was fixed.

07-05-2012, 12:34 PM
Here is a dumb question ( or just something I did not know) when you pull both grey 1 & 2 do they actually equalize and not drain completely? This has happened to me just recently, blak tank drained completely but the greys did not.

07-05-2012, 02:01 PM
Here is a dumb question ( or just something I did not know) when you pull both grey 1 & 2 do they actually equalize and not drain completely? This has happened to me just recently, blak tank drained completely but the greys did not.

The gray tanks cannot equalize on our unit since the tanks are not the same elevation. How can you be sure that both tanks did not drain completely? One may have and not the other. Not only are the tanks at a different level, the drains are on opposite ends of the tank. Some people will tell you to elevate the door side thinking that would drain the tanks completely, but that is not true on many rigs.

07-05-2012, 03:47 PM
I always drain my gray tanks one at a time, so I've never had that problem. I also never hook up my sewer hose until I'm leaving, unless we're staying longer than 2 days at any campsite. Reason being, anytime your sewer hose is out, there are many bad things that could happen to it (like animals, people accidentally brushing up against it and causing tiny holes, which are very messy when you do drain. When I do have the sewer hose hooked up, I never open/drain the tank until it's close to full. I never leave either the black or gray open during any stay, due to it causing anything draining out to sit and spoil inside the hose. Just my thoughts.......

Also, when you're leaving, if you have any left over ice, pour it down the toilet when adding your gallon or two of water and chemicals. Then while you're driving home or to your next spot, the ice will knock off anything that is sticking to the sides of your black tank.